Four pages.
One joined sheet.

Switch between the original pages and the actual stitched result. Download both files free to check them yourself.

Actual joined PDF: one continuous circle with crossing lines and a calibration square near the lower left
The lines meet across the joins. The red border marks are removed.
Page 1: upper left, with red marks in the border Page 2: upper right, with red marks in the border Page 3: lower left, with a calibration square Page 4: lower right
Four separate PDF pages, arranged left to right, then top to bottom.

Now check your own PDF.

Choose your pages and layout, then inspect a free proof. Pay $5 USD only if you want the stitched download. Printing is separate.

Use a supported PDF and your designer’s assembly guide. If your purchase includes a suitable copy-shop file, you can use that file already.